Ultraviolet pasteurizer

ABSTRACT

When an ultraviolet pasteurizer is used in a room free of a person, left and right light shield doors are opened to expose ultraviolet lamps outwardly. When an operation switch on a control panel is then turned on, an operation start timer is actuated, and the ultraviolet lamps are then energized to sterilize surrounding surfaces after elapse of 5 minutes. When the ultraviolet pasteurizer is used in a room occupied by a person, the left and right light shield doors are closed to direct the ultraviolet lamps inwardly until all light shield doors are brought into a substantially triangular prism. When the operation switch on the control panel is then turned on, the ultraviolet lamps and a fan are energized to draw external air from an air inlet. The drawn air passes through an inner radiation chamber defined inwardly of the light shield doors that have been combined into the substantially triangular prism. The air is sterilized by ultraviolet radiation emitted from the ultraviolet lamps and discharged from an air outlet.

TECHNICAL FIELD

[0001] The present invention relates to an ultraviolet pasteurizer for sterilizing an indoor space by the application of ultraviolet radiation.

BACKGROUND ART

[0002] Conventional ultraviolet pasteurizers for sterilizing an indoor space comprise an ultraviolet lamp that is energized to emit ultraviolet radiation to sterilize indoor walls and indoor air. The ultraviolet pasteurizers are basically classified into two types, i.e., one for applying ultraviolet radiation to indoor walls or the like and one for emitting ultraviolet radiation in a tubular member to sterilize indoor air that flows through the tubular member.

[0003] The former type of ultraviolet pasteurizer is disadvantageous in that since direct exposure to ultraviolet radiation is harmful to persons, no entry into the room is permitted while the ultraviolet pasteurizer is in operation or the application of ultraviolet radiation toward any person in the room needs to be inhibited.

[0004] The latter type of ultraviolet pasteurizer is also problematic in that it can sterilize microorganisms suspended in the air, but is unable to sterilize microorganisms attached to wall, ceiling, and floor surfaces.

[0005] It is therefore an object of the present invention to provide an improved ultraviolet pasteurizer which can be operated in different modes depending on whether there is a person in a room to be sterilized or not, for thereby solving the above problems.

DISCLOSURE OF THE INVENTION

[0006] To achieve the above object, there is provided an ultraviolet pasteurizer comprising an ultraviolet lamp, a light shield door openable and closable to block or pass ultraviolet radiation emitted from the ultraviolet lamp, an inner radiation chamber definable inwardly of the light shield door when the light shield door is closed, an air inlet and an air outlet providing communication between the inner radiation chamber and an external space, and a fan for introducing air from the external space via the air inlet into the inner radiation chamber, displacing the air near the ultraviolet lamp, and discharging the air from the air outlet.

[0007] If a room free of a person is to be sterilized by the ultraviolet pasteurizer, then the light shield door is opened and the ultraviolet lamp is energized to emit ultraviolet radiation. Since the ultraviolet radiation is radiated out of the ultraviolet pasteurizer, the ultraviolet pasteurizer can sterilize microorganisms attached to surrounding wall, ceiling, and floor surfaces and also microorganisms suspended in surrounding air.

[0008] If a room occupied by a person is to be sterilized by the ultraviolet pasteurizer, then the light shield doors are closed. The fan introduces external air from the air inlet into the inner radiation chamber, and flows near the ultraviolet lamp. The introduced air is thus sterilized by ultraviolet radiation emitted from the ultraviolet lamp. The sterilized air is then discharged from the air outlet. Microorganisms suspended in the air in the room can therefore be sterilized. Since the ultraviolet radiation emitted from the ultraviolet lamp is blocked by the light shield door and hence does not leak out of the ultraviolet pasteurizer, the ultraviolet pasteurizer can safely sterilize the occupied room.

[0009] Preferably, the ultraviolet pasteurizer may further include a main body, the light shield door being angularly movably supported on the main body, the ultraviolet lamp being mounted on the light shield door, the arrangement being such that when the ultraviolet radiation emitted from the ultraviolet lamp is to be radiated outwardly, the light shield door is angularly moved and held on the main body to expose the ultraviolet lamp outwardly, and when the ultraviolet radiation emitted from the ultraviolet lamp is to be radiated into the inner radiation chamber, the light shield door is angularly moved and held on the main body to direct the ultraviolet lamp into the inner radiation chamber. When the light shield door is opened, since the light shield door is angularly moved to direct the ultraviolet lamp outwardly, the ultraviolet lamp is exposed outwardly and hence the ultraviolet radiation emitted therefrom is not blocked. Consequently, the ultraviolet pasteurizer can sterilize a wide area uniformly.

[0010] Preferably, the light shield door may comprise a plurality of planar rectangular light shield doors angularly movably coupled to each other at side edges thereof, and the ultraviolet lamp may comprise a plurality of ultraviolet lamps mounted on respective sides of the light shield doors, the arrangement being such that when the light shield doors are to be closed, the side edges of the light shield doors are brought into abutment against each other with the ultraviolet lamps facing inwardly, and when the light shield doors are to be opened, the side edges of the light shield doors are brought into abutment against each other with the ultraviolet lamps facing outwardly.

[0011] The side edges of the light shield doors are angularly movably coupled to each other. For opening the light shield doors, the side edges of the coupled light shield doors are brought into abutment against each other with the ultraviolet lamps facing outwardly. Since the ultraviolet lamps can radiate ultraviolet radiation in an angular range of 360° in the circumferential direction, the ultraviolet pasteurizer can sterilize a wide area uniformly.

[0012] When the light shield doors are closed, the inner radiation chamber is defined in a space surrounded by the light shield doors. The ultraviolet lamps are accommodated in the inner radiation chamber. When air passes through the inner radiation chamber while the ultraviolet lamps are being turned on, the air can be sterilized. When the light shield doors are opened, the ultraviolet lamps are exposed. Therefore, the ultraviolet pasteurizer can sterilize surrounding wall, ceiling, and floor surfaces with ultraviolet radiation emitted from the exposed ultraviolet lamps. The range to which the ultraviolet radiation is applied can be adjusted by adjusting the degree of opening of the light shield doors. Thus, the ultraviolet pasteurizer can apply ultraviolet radiation only to a limited area which is free of persons.

[0013] Preferably, the main body may comprise a substantially triangular mount base disposed beneath the light shield doors, and the ultraviolet pasteurizer may further comprise a frame of substantially inverted U shape mounted on the mount base along one side thereof and extending upwardly, the light shield doors comprising three light shield doors which include a central light shield door having opposite side edges supported on the frame and held on the main body, and left and right light shield doors angularly movably mounted on the central light shield door by the frame.

[0014] The ultraviolet pasteurizer may preferably further comprise a power supply unit for supplying electric energy to the ultraviolet lamps and the fan, the power supply unit being disposed in a space surrounded by the light shield doors which are opened with the side edges held in abutment against each other so that the ultraviolet lamps face outwardly. When the light shield doors are opened to orient the ultraviolet lamps outwardly, a space is created by surfaces of the light shield doors which are free of the ultraviolet lamps. Since the power supply unit includes a transformer and other components, a space of certain size is required to accommodate the power supply unit therein. The power supply unit can be housed in the space thus created by the light shield doors. With the power supply unit housed in the space, the space can effectively be utilized, and hence the ultraviolet pasteurizer can be reduced in size.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a side elevational view of an ultraviolet pasteurizer according to an embodiment of the present invention.

[0016]FIG. 2 is a plan view of the ultraviolet pasteurizer shown in FIG. 1.

[0017]FIG. 3 is a perspective view of the ultraviolet pasteurizer shown in FIG. 1, with light shield doors being slightly open.

[0018]FIG. 4 is a plan view of the ultraviolet pasteurizer shown in FIG. 1, with the light shield doors being fully open.

[0019]FIG. 5 is a perspective view of an ultraviolet pasteurizer according to another embodiment of the present invention.

[0020]FIG. 6 is a perspective view of an ultraviolet pasteurizer with four light shield doors according to still another embodiment of the present invention.

[0021]FIG. 7 is an enlarged fragmentary perspective view of the ultraviolet pasteurizer shown in FIG. 6, partly in cross section taken along line VII-VII of FIG. 6.

BEST MODE FOR CARRYING OUT THE INVENTION

[0022] Embodiments of the present invention will hereinafter be described in detail with reference to the drawings FIGS. 1 through 7.

[0023] As shown in FIG. 1, an ultraviolet pasteurizer 1 according to an embodiment of the present invention has a light shield door assembly 2 housing ultraviolet lamps therein and disposed on a triangular mount base 4. The light shield door assembly 2 is angularly movably supported by a frame 7, described later on, and defines an inner radiation chamber R therein when the light shield door assembly 2 is closed as shown in FIG. 1. As shown in FIGS. 2 and 3, the light shield door assembly 2 comprises three planar rectangular light shield doors 2 a, 2 b, 2 c. The ultraviolet pasteurizer 1 has a plurality of vertically elongate ultraviolet lamps 3 mounted on inner surfaces of the light shield doors 2 a, 2 b, 2 c, with the central light shield door 2 a fixedly mounted on the mount base 4, and a main case 5 mounted on the mount base 4 and disposed on a reverse side of the central light shield door 2 a.

[0024] The light shield doors 2 a, 2 b, 2 c have respective reflective plates of stainless steel on respective inner surfaces thereof. As shown in FIG. 3, two parallel ultraviolet lamps 3 are vertically mounted on the surface of each of the reflective plates. Each of the light shield doors 2 a, 2 b, 2 c has an upper horizontal panel substantially in the shape of an isosceles triangle and has an air outlet 6 defined therein for ejecting air delivered from a fan 8, described later on. The air outlets 6 of the light shield doors 2 a, 2 b, 2 c are arranged to block ultraviolet radiation emitted from the ultraviolet lamps 3 against leakage out of the inner radiation chamber R. Of the light shield doors 2 a, 2 b, 2 c, the central light shield door 2 a is fixed to the frame 7, which is of a substantially inverted U shape, extending upwardly from the mount base 4. The left and right light shield doors 2 b, 2 c have side edges angularly supported on respective opposite side edges of the central light shield door 2 a by the frame 7. When the light shield doors 2 a, 2 b, 2 c are closed with the ultraviolet lamps 3 disposed inside, the inner radiation chamber R is defined in a space surrounded by the light shield doors 2 a, 2 b, 2 c, as shown in FIGS. 1 and 2. The frame 7 has an upper end for use as a handle to be gripped by the user when the ultraviolet pasteurizer 1 is carried.

[0025] As shown in FIG. 3, the fan 8 is mounted in the mount base 4 near the inner surface of the central light shield door 2 a. The mount base 4 has an air inlet 9 defined in the bottom thereof below the fan 8 for drawing external air into the inner radiation chamber R. In the present embodiment, an ozone generator (not shown) for generating ozone is disposed between the air inlet 9 and the fan 8. The main case 5 is disposed on the outer surface of the central light shield door 2 a. Casters 10 are mounted on the bottom of the mount base 4 for making the ultraviolet pasteurizer 1 movable. As shown in FIG. 2, the mount base 4 supports two door opening detecting switches 11 which can be turned on by being pushed by the light shield doors 2 b, 2 c when the light shield doors 2 b, 2 c are opened. As shown in FIG. 4, the mount base 4 also supports two door closing detecting switches 12 which can be turned on by being pushed by the light shield doors 2 b, 2 c when the light shield doors 2 b, 2 c are closed.

[0026] The main case 5 is of a substantially trapezoidal shape as viewed in plan such that the main case 5 is neatly accommodated within the light shield doors 2 a, 2 b, 2 c that are shaped into a substantially triangular prism when the left and right light shield doors 2 b, 2 c are opened with their ultraviolet lamps 3 facing outwardly, as shown in FIG. 4. As shown in FIG. 1, the main case 5 houses therein a power supply unit 13 for supplying electric energy to the ultraviolet lamps 3, the fan 8, and the ozone generator. The main case 5 has on its upper surface a control panel 14 for setting operating conditions for the ultraviolet pasteurizer 1. As shown in FIG. 1, the main case 5 also houses therein a controller 15 for controlling operating conditions for the ultraviolet pasteurizer 1.

[0027] Modes of use of the ultraviolet pasteurizer 1 will be described below with reference to FIGS. 2 and 4.

[0028] First, a mode for sterilizing a room free of persons will be described below. When the ultraviolet pasteurizer 1 is to be used in an unoccupied place, the left and right light shield doors 2 b, 2 c are opened laterally to place their ultraviolet lamps 3 facing outwardly. When the light shield doors 2 b, 2 c are fully folded back, the door opening detecting switches 11 are turned on, whereupon the controller 15 detects the full opening of the light shield doors 2 b, 2 c. In the present embodiment, the ultraviolet lamps 3 can be energized when both the opening detecting switches 11 are turned on.

[0029] Then, when an operation switch (not shown) on the control panel 14 is turned on with the light shield doors 2 a, 2 b, 2 c being fully open, an operation start timer is actuated, and the ultraviolet lamps 3 are then energized after elapse of 5 minutes. When the ultraviolet lamps 3 are energized, they emit ultraviolet radiation to sterilize microorganisms attached to indoor walls, ceiling, and floor to which the ultraviolet radiation is applied. the ultraviolet radiation emitted from the ultraviolet lamps 3 also sterilizes microorganisms suspended in the air in the room.

[0030] A mode for sterilizing a room occupied by persons will be described below. In such a room, no ultraviolet radiation should be radiated out of the ultraviolet pasteurizer 1. Therefore, the ultraviolet pasteurizer 1 is used with the light shield doors 2 a, 2 b, 2 c being closed. First, as shown in FIG. 2, the left and right light shield doors 2 b, 2 c are closed with their ultraviolet lamps 3 facing inwardly until the light shield doors 2 a, 2 b, 2 c are brought into a substantially triangle prism, whereupon the inner radiation chamber R is formed in the space surrounded by the light shield doors 2 a, 2 b, 2 c. At this time, the door closing detecting switches 12 are turned on, allowing the controller 15 to detect the fully closure of the light shield doors 2 b, 2 c. In the present embodiment, the ultraviolet lamps 3 can be energized when both the door closing detecting switches 12 are turned on.

[0031] When the operation switch on the control panel 14 is turned on with the light shield doors 2 a, 2 b, 2 c being closed, the ultraviolet lamps 3 and the fan 8 start operating. When the fan 8 operates, it draws external air from the air inlet 8, and discharges the drawn air through the inner radiation chamber R from the air outlet 6. At this time, the air passing through the inner radiation chamber R is sterilized by the ultraviolet radiation emitted from the light shield doors 2 a, 2 b, 2 c. Therefore, microorganisms suspended in the air in the room are sterilized. In the present embodiment, since the ozone generator, not shown, is incorporated in the ultraviolet pasteurizer 1, the ultraviolet pasteurizer 1 can not only sterilize the air in the room, but also deodorize the air in the room.

[0032] In the above embodiment, the ultraviolet lamps 3 are energized only when the light shield doors 2 a, 2 b, 2 c are fully opened or fully closed. However, the ultraviolet lamps 3 may be made energizable when only one of the light shield doors 2 a, 2 b, 2 c is opened and the others are closed. For example, even when a room is occupied by a person, the ultraviolet pasteurizer 1 can direct ultraviolet radiation toward an area free of the person to sterilize indoor walls, ceiling, and floor in that area.

[0033] In the above embodiment, the light shield doors 2 a, 2 b are angularly movably coupled to each other and the light shield doors 2 a, 2 c are angularly movably coupled to each other, and when the left and right light shield doors 2 b, 2 c are angularly moved to open or close the light shield doors 2 a, 2 b, 2 c. However, the light shield doors 2 a, 2 b are angularly movably coupled to each other and the light shield doors 2 b, 2 c may be angularly movably coupled to each other at their side edges.

[0034] An ultraviolet pasteurizer according to another embodiment of the present invention will be described below with reference to FIG. 5. Those parts of the ultraviolet pasteurizer shown in FIG. 5 which are identical to those of the ultraviolet pasteurizer shown in FIGS. 1 through 4 are denoted by identical reference characters, and will not be described in detail below. As shown in FIG. 5, an ultraviolet pasteurizer 5 a has substantially cylindrical tubular members 16 a, 16 b, 16 c vertically mounted on a mount base 4. The tubular members 16 a, 16 b, 16 c accommodate respective vertically elongate ultraviolet lamps 3 therein. The tubular members 16 a, 16 b, 16 c have respective vertically elongate openings 17 defined therein which extend about 120° in the circumferential direction. Each of the openings 17 can be opened and closed by two light shield doors 2. The light shield doors 2 are slidable in the circumferential direction along the opening 17 to open and close the opening 17. When the light shield doors 2 are closed, each of the tubular members 16 a, 16 b, 16 c defines an inner radiation chamber R therein. The mount base 4 has an air inlet 9 defined therein below the tubular members 16 a, 16 b, 16 c for introducing air to be drawn by fans 8 housed in the mount base 4. The tubular members 16 a, 16 b, 16 c have air outlets 6 defined in upper ends thereof for discharging air that has passed upwardly through the tubular members 16 a, 16 b, 16 c.

[0035] The ultraviolet pasteurizer 1 a operates as follows: When the openings 17 in the three tubular members 16 a, 16 b, 16 c are opened and the ultraviolet lamps 3 are energized, the ultraviolet pasteurizer 1 a emits ultraviolet radiation therearound to sterilize surrounding wall, ceiling, and floor surfaces. Alternatively, the opening 17 in the tubular member 16 a may be opened and the openings 17 in the other tubular members 16 b, 16 c may be closed to apply ultraviolet radiation to only a limited indoor area to sterilize wall, ceiling, and floor surfaces therein. At the same time, the fans 8 in the other tubular members 16 b, 16 c are operated, and the ultraviolet lamps 3 in these tubular members 16 b, 16 c are energized to emit ultraviolet radiation in the inner radiation chamber R. Since air drawn from the air inlet 9 is sterilized in the inner radiation chamber R and then discharged from the air outlet 6, the air in the room can also be sterilized.

[0036] An ultraviolet pasteurizer with four light shield doors according to still another embodiment of the present invention will be described below with reference to FIGS. 6 and 7. Those parts of the ultraviolet pasteurizer shown in FIGS. 6 and 7 which are identical to those of the ultraviolet pasteurizer shown in FIGS. 1 through 5 are denoted by identical reference characters, and will not be described in detail below. As shown in FIGS. 6 and 7, an ultraviolet pasteurizer 1 b is of a cylindrical shape in its entirety and has four light shield doors 2 which support respective ultraviolet lamps 3. Each of the light shield doors 2 is angularly movable about 180° about a vertical shaft 18. In FIGS. 6 and 7, only one of the light shield doors 2 is angularly moved to have its ultraviolet lamp 3 exposed outwardly. A mount base 4 houses a fan (not shown) housed therein, and has an air inlet 9 defined in the bottom thereof. The four light shield doors 2 have respective upper ends pivotally supported by an upper case 19 having an air outlet 6 defined therein. The upper case 19 is coupled to the mount base 4 by a vertical central shaft 20 shown in FIG. 7.

[0037] The ultraviolet pasteurizer 1 b operates as follows: When all the four light shield doors 2 are turned to have their ultraviolet lamps 3 exposed outwardly, the ultraviolet pasteurizer 1 b emits ultraviolet radiation therearound to sterilize surrounding wall, ceiling, and floor surfaces. Alternatively, when only one of the light shield doors 2 is turned to expose its ultraviolet lamp 3 outwardly, as shown in FIGS. 6 and 7, only the outwardly facing the ultraviolet lamp 3 emits ultraviolet radiation outwardly to apply ultraviolet radiation to only a limited indoor area to sterilize wall, ceiling, and floor surfaces therein. When all the light shield doors 2 are closed, ultraviolet radiation is emitted from all the ultraviolet lamps 3 into the inner radiation chamber R surrounded by the light shield doors 2. The fan housed in the mount base 4 introduces external air from the air inlet 9. The introduced air flows upwardly through the inner radiation chamber R, is sterilized by the ultraviolet radiation emitted from the ultraviolet lamps 3, and is then discharged from the air outlet 6.

[0038] In the above embodiments, the ultraviolet pasteurizer has three or four light shield doors. However, the ultraviolet pasteurizer may have two or five or more light shield doors. For example, the central light shield door 2 a may be dispensed with, and an ultraviolet lamp 3 may be mounted on the back of the main case 5, with only two left and right light shield doors 2 b, 2 c being used as light shield doors. If a plurality of light shield doors are angularly movably coupled at side edges thereof, they may be directly coupled to each other or may be coupled by a connecting member such as the frame 7.

INDUSTRIAL APPLICABILITY

[0039] The present invention is useful as an ultraviolet pasteurizer for sterilizing an indoor space by the application of ultraviolet radiation. 

What is claimed is:
 1. An ultraviolet pasteurizer comprising: an ultraviolet lamp; a light shield door openable and closable to block or pass ultraviolet radiation emitted from said ultraviolet lamp; an inner radiation chamber definable inwardly of said light shield door when said light shield door is closed; an air inlet and an air outlet providing communication between said inner radiation chamber and an external space; and a fan for introducing air from the external space via said air inlet into said inner radiation chamber, displacing the air near said ultraviolet lamp, and discharging the air from said air outlet.
 2. An ultraviolet pasteurizer according to claim 1, further comprising: a main body, said light shield door being angularly movably supported on said main body, said ultraviolet lamp being mounted on said light shield door; the arrangement being such that when the ultraviolet radiation emitted from said ultraviolet lamp is to be radiated outwardly, said light shield door is angularly moved and held on said main body to expose said ultraviolet lamp outwardly, and when the ultraviolet radiation emitted from said ultraviolet lamp is to be radiated into said inner radiation chamber, said light shield door is angularly moved and held on said main body to direct said ultraviolet lamp into said inner radiation chamber.
 3. An ultraviolet pasteurizer according to claim 2, wherein said light shield door comprises a plurality of planar, substantially rectangular light shield doors angularly movably coupled to each other at side edges thereof, and said ultraviolet lamp comprises a plurality of ultraviolet lamps mounted on respective sides of said light shield doors, the arrangement being such that when said light shield doors are to be closed, the side edges of the light shield doors are brought into abutment against each other with the ultraviolet lamps facing inwardly, and when said light shield doors are to be opened, the side edges of the light shield doors are brought into abutment against each other with the ultraviolet lamps facing outwardly.
 4. An ultraviolet pasteurizer according to claim 3, wherein said main body comprises a substantially triangular mount base disposed beneath said light shield doors, further comprising a frame of substantially inverted U shape mounted on said mount base along one side thereof and extending upwardly, said light shield doors comprising three light shield doors which include a central light shield door having opposite side edges supported on said frame and held on said main body, and left and right light shield doors angularly movably mounted on said central light shield door by said frame.
 5. An ultraviolet pasteurizer according to claim 3 or 4, further comprising: a power supply unit for supplying electric energy to said ultraviolet lamps and said fan, said power supply unit being disposed in a space surrounded by the light shield doors which are opened with the side edges held in abutment against each other so that said ultraviolet lamps face outwardly. 